Titration Study of ABX-1431

Key Inclusion Criteria: * Patient is a male or female over the age of 18 years of age at the Screening Visit. * Patient has a peripheral neuropathic pain in one of the following diagnostic groups that is persistent for \> 3 months * Post-herpetic neuralgia * Diabetic peripheral neuropathy * Small fiber neuropathy * Post-traumatic neuropathic pain * Patient's median NRS-11 pain intensity score must be ≥ 4 during the baseline period * If a patient enters the trial on daily background neuropathic pain medications, then the patient must be on stable dose of medications for at least 30 days before enrollment and throughout the study. * Patient is able to understand and comply with the protocol procedures for the entire trial and must give written informed consent. * Men and Women must agree to a medically approved contraceptive regimen. Key Exclusion Criteria: * Patient is taking potent cytochrome P450 3A4/5 inducers or inhibitors * Patient has received injection therapies (e.g., botulinum toxin, anesthetic or nerve block) or transcutaneous electrical stimulation to control pain in the past 60 days * Patient has evidence of alcohol, drug or chemical abuse in the year before the Screening Visit. * Patient is a lactating or pregnant female or a female who intends to become pregnant within 90 days following the last dose of investigational product. * Patient has specific laboratory abnormalities Other protocol-defined inclusion/exclusion criteria may apply.